Manufacture of glass sheets.



-UNITED STATES PATENT OFFICE.

WILLIAM L. CLAUSE, OF SEWICKLEY, AND HALBERT K. HITCHCOCK, OF

. IARENTUM, PENNSYLVANIA.

Specification of Letters Patent.

MANUFACTUREOF GLASS SEHEETS.

Patented Oct. 9, 1 906.

Application filed January 10,1906. 1 Serial No. 295,451.

venia, citizens of the United States, have invented or discovered certain new and useful yond certain-dimensions. this method it is found that hnes some-- shell formed when the colder surface ofg'the Improvements in the Manufacture of Glass- Sheets, of which improvements the following is a s ecification. g

In etters Patent Nos. 805,064 and 805,065, dated November 21, 1905,28. method of and apparatus for manufacturing glass sheets is described and claimed, said method consisting, generally stated, in "causing afiow of molten glass throu'gha slot orifice, or channel and then up lying to the glass as it exudes from such at or opening a pull or tensionwhereby theglass is drawn to sheet form. In passing through the slot or opening the outer ortion or layers of the stream of glass will a here to the Walls of such slot or opening, thereby forming an anchorage for such' outer layer or portions,- so that when tension is applied a stretch or elongation of the glass can occur. When a plastic substance, such as molten glass, is subjected to a pull or tension such as that described above, there is a constant tendency for the fining down or reduction of the cross-section of the aterial. In the method described this tendency to reduction or fining down is preventedby the feeding in of the middle portions or portion of the stream of glass into the thin-walled less is subjected to tension, the glass hus ed in preventing the indravvin or fining be- In t ,e practice of times occur on the finished sheet, due, it is believed, either to the chilling of minute porthese cooled particles are subjected to the stretch or elongation, they will produce fine hair-like lines on the. surface ofthe sheet,

thereby reducing itsvalue as a marketable article.

The invention described herein has for its object the maintenance of the surface of the to the tank-furnace 1.

lass at the formative point or point of sheet ormation produced by the applied tension at a uniformly-constant temperature; and it is a further object of the invention to feed through the slot, orifice, or channel an amount of glass greater than that required to form the desired sheet and to cause this so glass, to flow awa from the direction of s eet formation, there y preventing the entrance ofanv chilled particles from the anchorage into the sheet being formed.

The iIIVQHtlOIlJS hereinafter more fully' described and claimed.

In the accompanying drawings, forming a part off'this specification, Figure 1- is a sec:- tional lan view of aform of apparatus adapted to t e practice of our invention. Fig. 2.is a sectional elevation, the lane ofs'ection be ing indicated by theline I II, Fig. 1.. Fig.

3 is a sectional detail view illustratin ar method of causing the outward flow of t e surplus glass fromthe direction of sheet formation. Fi 4is a' similar view. showin another met 0d of producing such outwar flow, and Fig. 5 is a view illustrating the man-' nor of initiating the process or method illustrated in Fig. 4.

The mainten ance-of a constant temperature at the point of sheet formation can be effected in man ways-as, for exam le, by regulating the ow of glass from the s ot or orifice,

The greater such flow the higher will.be the temperature of the glass at the pointof sheet formation, or the maintenance of such uniform temperature may beattained by the application of heat at the formative point.

the practice of the invention the slot or origo fice 5, which has a shape corres onding approximately toth t of the artic e to be produced, is connected by a channel 3 to a suitable source of supply-such, for exam 10, as

' The forced lass through the channel and from the orice can be effected by any suitable means such, forexample, as the maintenance of the level of the glass in the furnace above the lane of the slot 5, as shown in Fig? 2-the liighe'r the level of glass in the chamber above the slot the greater the. flow or exudation therefrom. ployed for regu ating this flow through the channelsuch, 'for example, as a fioatin stopper 2, which is provided with inclined An suitablemeans may be emfaces 2 adapted to move along similar faces 2" in the end wall of the furnace when the stopper. is shifted longitudinally, there by ei ther forcing the stopper away from the outlet 3 or permitting itto move inward and close such outlet. This longitudinal shifting of the stopper can readily be effected by means of a rod passed through openings 4; in the side walls and engaging the stopper.

The outward-flow of the surplus glass from the direction of sheet formation can be effected in many Vay..as, for example, in Fig. 3 provision is made to allow the surplus glass to flow outwardly under the action of gravity over the end walls of the slot. It will be readily understood that when the glass flows by gravity, as shown in ig 3, the greater the feed through the slot the quicker will he the outward flow, and the glass at the formative point will be ma n aimed at a higher temperature; but if the flow through the slot is slow the outward flow will be correspondingly slow, and thus affording an opportunity for the cooling of the glass up into close proximity to the formative point or point of applied tension By this means a regulation of the temperature at the formative point can be attained. The outward flow of the glass from the formative point can be regulated by varying the inclination of the top surface of the slot-wall. It is referred, however, to employ means where y a more positive and certain outward movement of the. surplus glass from the slot can be attained. A suitable means to this end consists of several series of rolls 7, arranged in such relation to the slot that the outwardlyflowing glass will rest thereon and be moved outwardly by the frictional contact of such rolls with the glass. As will be seen by reference to Figs. 1 and 2, series of such feeding-rollers are arranged opposite each side and edge of the glass as it exudes from the slot, so that by the action of these rollers the glass will be drawn away in opposite directions. It will be understood that the number of these feed devices can be increased or diminished, as required by the ha ie of the article to be produced. lVhile the frictional engagement of the rollers with the outwardly-' moving glass will generally be sufiicient to insure the re uired movement, it is preferred to em oy rollers 6, arranged above one of the rol crs of each of the series, so that there will be a bite of these rollers 6 and 7 on opposite sides of the glass. Each of the series of rollers may be driven independently or, as shown, from a common motor.

Any suitable means maybe employed for applying tension to the exuding glass for the purpose of forming sheets-such, for example, as that shown and described in applications for Letters Paten ,Serial Nos275i62 and 275,463, filed August 23, 1905, by ll. K.

.such relation to the slot that glass exuding therefrom would adhere to the bait. When positively-acting means are employed for causing the outward flow of the glass, similar baits 15* are arranged so that their inner ends will be adjacent to the slot, while their outer portions are within the bites of the-- feeding-1ollers. As 'soon as these baits are suitably arranged and heated the glass is permitted to flow from the tank through the channel and exude from the slot or opening. As it rcachesthe slot or opening it will adhere to the heated ends of the baits, and when the rollers 12 and the feed-rollersfli and 7 are started in operation there wilhbe a movement of the glass vertically to form a sheet and laterally by the rollers 6 and 7. It will be understood that the rate of this latter movement of the will be determined. by the conditions attendant on the formation of the sheet. If a higher surface temperature is required at the formative point the flow of glass through the channel 3 and the rotation of the rollers 6 and 7 are so regulated that there wil be a more rapid flow of hot glass to the formative point. if, however, a lower surface temperature is required at the slot or opening, the speed of the rollers 6 and 7 and the rate of feed of the glass to the slot are so adjusted as to permit of a reductionof surface temperature at the formative point. In addition to thus providing for the regulation of the temperature and the main-.

tenance of an approximately constant surface ten'iperature at the formative point the outward movement of the glass from the formative point at an angle to the direction of sheet formation will carry away any cooled particles which may become detached from the anchorage from the direction of sheet formation and will not, therefore become incorporated in the sheet, and, further, the stains or blemishes which are sometimes found in the outer portion of the stream of glass flowing through the slotwill he carried away with the ou twardly-ilowing glass, and only glass from theinterior portions of such stream will be formed into the principal sheet.

it is characteristic of our improved method that, in effect, we provide a constantl changing anchor for the glass which is to e formed into the thin shell or outer surfaces of the finished sheet and also for the removal of any cooled glass from the point of sheet formation. It is a further characteristic of the invention that those portions of the glassi. 0., the outer portionswhich are most liable to contain imperfections or ble1nishes are not incorporated in the principal product, but are drawn outward away from the core or inner portion of the exuding glass, which is formed, as shown in Figs. 3 and 4, into the principal prod net. The glass which is drawn away from the line of sheet forl'nation may be utilized by the employment of suitable eans--as, for example, in the constructior shi'iwn the outwardl v-drawn glass can he reduced to sheets, which, although inferior to the principal product, would have a marketable value.

It will be understood by those skilled in the art that by varying the relative rate ol" movement the glass formed in the principal product and that ol' the glass drawn away from. the plane of formation of the principal product the position of the point of tormation can be varied withinwidc limits.

o claim herein as our in.vention 1. As an improvement in the art of manufacturing glass articles, the method herein described which consists in causing the glass more directions at an angle to each other,

2. Asan improvement in the art of manufacturing glass articles, the method herein described which consists in causing glass to flow through a slot or orifice causing such exuding glass to move away from the slot or orifice in two or more streams and imparting to such streams ofglass the desired shape or contour.

3. As an improvement. in the art of manufacturing glass articles, the method herein described which consists in causing glass to ilow through a slot or orifice, drawing portions of the exuding glass at an angle to and away from the stream and drawing another portion of the exuding glass in or approximately in the plane of the stream through. the orifice or opening.

4. As an improvement in. the art of manufacturing glass: articles, the method herein described which consists in causing glass to flow through a slot or orifice, drawing the outer portions of the exuding stream in directions at an angle to and out ol the line offlow and drawing the core or inner portions 5. As an improvement inthe art of manufactoring glass articles, the 'method herein described which consists in causing a greater flow of glass through a slot or orifice than is required to Form the desired article, causing a portion of such glass to assume the desired shape and removin the surplus glass from the point of formation of the principal product. I

6. As an improvement in the art of manufacturing glass articles, the method herein described which consists in causing a flow of glass through a slot or orifice, applying a forming tension to a portion of the exuding glass and regulating the siu'Face temperature of the glass at the point of formation by causing a portion of the exuding glass to flow away from the direction oi formation of the principal product. 7. As an improvement in the art 01? manufacturing glass articles, the method herein described which consists in causing, a greater low of glass to a given point than is required to form the desired article, causing a portion of such glass to assume the desired shape, and removing the surplus glass from the point of formation of the desired product.

'8. As an improvement in the art oi manu facturing. glass articles, the method herein described which consists in causing the surface glass of the body of metal to move away from a given. point and causing the from the interior ol the body to assume the desired shape.

9. In an apparatus for the manufacture of glass articles the combination. of a slot or rrilice, means for causing a flow of glass through the slot or orifice, means for applying tension to glass exuding from the slot or orifice in the direction of [low thri'nigh the slot or orifice, and means for drawing glass away from the direction of applied tension whereby the, glass is divided into two or more streams or bodies as it exudes from the slot.

In testimony whereof we have hereunto set our hands.

W'lILliIAitl. L. CLAUSE. HALBERT K. l'iITCIiCOUK. Vi tnesses:

H. S. VniaNnrr, L. 'l Wmrrmtn. 

